1. Field of the Invention
The present invention relates to a terminal with its contact section penetrating an insulated wire and an electrical connector having the terminal.
2. Description of the Related Art
An example of such a terminal and an electrical connector is disclosed in Japanese patent application Kokai No 11-345640. As shown in FIG. 4, this connector comprises a housing 51 made of an dielectric material so as to have a slot 51A extending in parallel to the sheet and a terminal 52 made of a metal sheet without bending. A plurality of such slots are arranged at regular intervals in the third direction perpendicular to the sheet to receive terminals 52 one for each slot.
The terminal 52 has an upper fixing arm 53 and a lower flexible arm 54. The fixing arm 53 is provided with a rotation support 53A, and the flexible arm 54 are provided with two contact portions 54A at its tip. As shown in FIG. 5, the contact portions 54A are tapered to the upper edge.
Referring back to FIG. 4, a rotary pressure member 55 is rotatable between the open position indicated in broken line and the closed position indicated in solid line. It extends in the third direction to cover the entire range of the terminals. It has a depending pressure section 55A in which a cable-receiving groove 55B extends in alignment with the slot 51A.
In use, bringing the pressure member 55 to the open position makes a space between the pressure member 55 and the contact section 54A of the terminal, which is sufficiently large to receive a flat cable C or the like. Then, the pressure member 55 is rotated to the closed position so that the bottom of the cable-receiving groove 55B presses the cable C against the contact section 54A. When the cable C is pressed against the contact section 54A, the contact section 54A of each terminal penetrates the insulation of the cable to make contact with the core wire, making electrical connection.
However, this connector suffers poor contact between the terminal and the core wire.
As shown in FIG. 5, the contact section 54A penetrates the insulation C2 of the cable C to make contact with the core wires C1. However, many core wires C1 are pushed aside by the contact section 54A so that not only the contact pressure decreases but also some of the core wires do not come to contact with the contact section 54A, reducing the contact area. This happens because the contact section 54A extends in the same direction as the core wires.
Accordingly, it is an object of the invention to provide a terminal capable of keeping good contact with core wires and an electrical connector having such a terminal.
According to an aspect of the invention there is provided a terminal comprising an elongated piece of metal sheet having a front portion and a contact section provided on an upper edge of the front portion. The contact section has a central crest portion for penetrating the insulation of a cable to come to contact with a plurality of core wires of the cable and a pressure faces extending outwardly from the crest portion for compressing the core wires, thus minimizing the electrical resistance.
When the cable is pressed against the terminal, the contact section penetrates the insulation of the cable to enter among the core wires. The pressure faces presses the core wires, providing high contact pressure and large contact area.
According to another aspect of the invention there is provided an electrical connector comprising a housing for supporting such terminals as described above and a pressure member for pressing the cable against the terminal. The pressure member comprises a cable-receiving groove having side walls that restrict lateral expansion of the cable when the contact section penetrates the cable.
According to still another aspect of the invention there is provided an electrical connector comprising a terminal having a contact section for penetrating the insulation of a cable to come to contact with core wires of the cable and a pressure member having a cable-receiving groove for receiving and pressing the cable against the contact section. The cable-receiving groove has a primary receiving groove for receiving the cable before the contact section penetrates the insulation; a secondary receiving groove in which the cable is pushed by the contact section and having side walls for restricting lateral expansion of the cable when the contact section penetrates the cable; and a neck section for communicating the primary and secondary receiving grooves and having a width that is smaller than a diameter of the cable but sufficiently large to allow the cable to pass through by deformation under pressure.
When the cable in the primary receiving groove is pressed against the contact section of the terminal, the crest portion enters among the core wires and pushes the cable into the secondary receiving groove. The side walls of the secondary receiving groove prevents expansion of the cable so that the contact section makes contact with many core wires under high contact pressure, increasing the contact area.
The neck section has a width that gradually decreases toward the secondary receiving groove to not only facilitate insertion of the cable into the secondary receiving groove but also assure catch of the cable by the contact section.